Isotope effects on the 13 C chemical shift and carbon–proton coupling constant in dichloromethane

Carbon–proton and carbon–deuteron coupling constants were measured in the isotopomers CH 2 Cl 2 , CHDCl 2 and CD 2 Cl 2 . The primary and secondary isotope effects on the carbon–proton coupling are −0.60 (±0.05) and −0.25 (±0.01) Hz, respectively. The deuterium‐induced 13 C isotope shifts proved to be almost linearly dependent on the number of deuterium atoms, although there is a small but significant non‐additivity.